In October 2009, the Advisory Committee on Immunization Practices (ACIP) approved a newly licensed vaccine, Cervarix, directed against human papillomavirus (HPV) to prevent cervical cancer. The ACIP also expanded its recommendations against HPV by giving permission to physicians to vaccinate males aged 9 to 26 years with the previously licensed vaccine, Gardasil, to prevent genital warts, in addition to its previous recommendation for females aged 9 to 26 years to prevent cervical cancer and genital warts. The marketing, expense, safety, and reactivity of Gardasil continue to be the subject of controversy. Of the >100 types of HPVs, approximately 40 are sexually transmitted, and HPV is the most common sexually transmitted disease. By age 50 years, 80% of women will have contracted a sexually transmitted HPV infection. While most individuals are clear of infection by 2 years, some types of HPV carry a high risk for progressing to cancer, and HPV is identified in >99% of patients with cervical cancer. Each year in the United States approximately 12,000 women develop cervical cancer and nearly 4000 die of it. Human papillomavirus is also associated with genital warts and other anogenital cancers. The United States has now licensed 2 vaccines against HPV, Gardasil and Cervarix. Gardasil has been shown to be safe and effective in preventing HPV infections by types 6, 11, 16, and 18; types 16 and 18 are associated with 2 high-risk types of cervical cancer and are associated with 70% of all cervical cancers. Types 6 and 11 are associated with 90% of anogenital warts. Cervarix has also been shown to be safe and effective in preventing HPV infections by types 16 and 18, but offers no known protection against anogenital warts.